1. Field of the Invention
The present invention generally relates to the field of implantable medical devices. More specifically, the present invention relates to a suture sleeve for securing an implantable lead to body tissue.
2. Description of the Prior Art
Suture sleeves are used for securing a lead to a patient's body tissue, for instance a lead used for electrical connection between a heart stimulator, e.g. a pacemaker, and a heart. The purpose of the suture sleeve is to provide an aid for suturing and fixating the lead at a desired position in the body, which in the field of heart stimulators generally is at the point of entry into a vein. Thus, the suture sleeve is arranged to fixate the sleeve at a selected position along the lead, and often presents a guiding groove, or the like, into which the suture can be tied.
U.S. Pat. No. 5,273,053 discloses a suture sleeve, which is adapted to secure a lead to a patient's body tissue. The suture sleeve comprises a sleeve body, which has a longitudinal through bore to receive the lead and a perpendicular channel intersecting the longitudinal through bore, and a pushbutton lock member. The pushbutton lock member is movable within the perpendicular channel and has a through bore dimensioned to receive the lead. Further, the pushbutton lock member may upon depression of the lock member be moved laterally from a first position, in which the lead may run freely within the sleeve, to a second position, in which the lead is fixed in position in relation to the sleeve. In order for the lock member to release the lead to move freely within the sleeve, the lock member must be returned to the first position be pressing the opposite side of the lock member, which may be a delicate and difficult operation, especially when the sleeve and lead are positioned inside the body during implantation.
U.S. Pat. No. 5,603,730 discloses another example of a suture sleeve. The sleeve has an elongated body which defines a bore and is provided with a relief aperture at a first intermediate position on the body and communicating with the bore. Said sleeve includes a pair of actuator tabs attached at a second intermediate position on the body and extending laterally therefrom. At least a portion of the relief aperture is positioned between the tabs such that actuation of the tabs causes enlargement of the aperture. The sleeve is movable between a tighter state, in which a lead passing through the bore does not readily slide longitudinally within the bore, and a looser state, in which the lead may slide readily through the bore. Thus, the actuator tabs must be continuously manipulated when the sleeve is to be moved along the lead.
Currently, the technological development within the field of heart stimulators is moving towards thinner and thinner leads. This puts higher demands on the properties of the suture sleeve in order to meet the requirements of ever thinner leads, in terms of safe and convenient handling of the sleeve and avoiding the risk of suture tie-down damages to the lead.